Fiber treatment



Oct. 3, 1939. J. P. TARBox 2,174,863

FIBER TREATMENT Filed June 22, 19:57

PlCli Patented Oct. 3, 1,939

UNITED STATES PATENT OFFICE FIBER 4TREATMENT Application June 22, 1937,Serial No. 149,641

2 Claims.

This invention relates to improvements in apparatus for and method oftreating textile fibers and more particularly to the continuoustreatment of an untwisted high denier roving such as rayon staple.

During the production of continuous bers such as rayon fibers, certainof the steps include the treatment of the fibers in one of more liquidbaths and it has heretofore been suggested that the path of the rovingbe into and outof a suitable liquid by which a. continuous washing ofthe roving iilaments in the liquid is brought' about.

I have discovered, however, that contrary to prior belief, a continuousuniform passage of the roving through the bath does not give the moste'ective washing of the filaments by the liquid and this is apparentlydue to the carrying of' partially spent liquid within the roving. I iindthat a variation in the tension of the roving as it passes through thebath is far superior to a uniform tension as this change of tensioncauses a squeezing out of partially spent liquid and an absorption ofthe unspent liquid from the bath. This movement of the liquid throughthe roving also increases the surface area available to contact with theliquid thereby bringing about a more elcient treatment.

It is one of the principal objects of my invention to provide animproved method of treatment of continuous roving in a liquid treatingmedium in which the roving is fed continuously through the bath butl issubjected to repeated changes of tension by which absorption andsqueezing out f of the liquid between the filaments is obtained.

A further object of my invention is to provide an improved apparatus forthe continuous treatment of fibers such as artificial rayon rovinghaving a large number of filaments in which means is providedfor varyingthe tension of the filaments during their passage through the bath.

A further and more detailed object 'of the invention is to provide asimplified eccentric drive for one of a pair of rolls over which atextile roving is carried, such rolls being mounted in a liquidtreatment tank with the distance between the rolls being repeatedlychanged by the eccentric movement thereby causing the roving between therolls to swell up under absorption of liquid when the path is shortestand then to discharge the liquid when the path is greatest.

Further objects and advantages of my invention will appear fromthefollowing description of preferred form of embodiment thereof takenin connection with the attached drawing illustrative thereof and inwhich:

Fig. lis a diagrammatic end elevation of a treating bath havinghorizontally positioned rolls, v

Fig. 2 is a plan view of the eccentrically mounted roll with parts ofthe bearings shown in section, and

Fig. 3 is a diagrammatic end elevation of a modified form of apparatus.V

In the preferred form of embodiment of my invention, a liquid treatingbath, generally indicated at III, is adapted tobe used for continuouslytreating a high denier roving generally indicated at I2. Moreparticularly, the roving is rayon having hundreds of separate filamentsas for forming an untwisted staple of substantial size.. It is to beunderstood, howeverthat the apparatus is useful for other bers.

The multiple strand roving I2 is conducted on a continuous circuitthrough the bath by passing it over an upper roll or cage I and a lowerroll or cage I5 which are preferably horizontal. The roving I2 aftermaking the necessary or desired number of loops around the respectiverolls III and I5 then discharges from the tank as shown at I2a. Atension is preferably maintained on the ends of the roving as by tensiondevices ISI` which may be urged by springs or other means against theentering and exit roving I2 and I2a. i In order to increase theeffectiveness of the liquid contact, I repeatedly change the tension onthe roving within the tank to squeeze out the partially spent liquid.This may be eii'ectively accomplished by an eccentric mounting of one ofthe rolls such as the upper roll I4 by using crank arms I6 having abearing mounted portion I'I. 'Ihe crank arms are rotated by suitabledrive means such as gear I8 and the lower roll which is mounted on aconcentric axis will be rotated by the top roll. The lower roll,however, is permitted to move towards and away from the eccentric rollin guide means 2l in order to prevent undue tension otherwise likely tobreak the roving. The upper roll rotates on an eccentric path asindicated by the dotted lines with the result that the length betweenthe reaches I2b and I2c of theroving is changed. In addition, thereaches move laterally as shown by the dotted position of the rovingwithin the bath. The illustration exaggerates this movement.

The movement of the roving from one dotted position to the other causesa form of washing action but primarily the reduction of tension allowsthe bers to balloon out and absorb a greater amount of the treatingliquid than when the tension is increased. This repeated tensioning andloosening of the roving and lateral dise placements occurs many timesduring the passage of the roving through the treating bath and thus setsup a liquid exchange between the respective iilaments of the roving andthe treating bath.

As shown in Fig. 2, the roll Mis of a suitable length and constructionas required by circumstances and each roll may be directly driven. Therolls I 4 and I5 are preferably in askew relation with each other tomake a helical transfer of the\roving axially of the rolls through thetreating liquid.

If desired, the lower roll I5a may be eccentrically mounted such asshown in Fig. 3 with the upper roll Ha on a central axis. The operationenvases bodiment of my invention, I am aware that other modificationsmay be made thereto and I therefore desire a broad interpretation of myinvention within the scope and spirit of the description herein and ofthe claims appended hereinafter.

What I claim is:

1. An apparatus for continuously treating a roving having a plurality offilaments in a liquid bath which includes a pair of circular rolls insaid bath over which said roving continuously passes and means to varythe tension of said roving and its path through the bath during itsprogress around said rolls whereby the absorption of the roving isperiodically changed, said tension varying means including an eccentriccrank mounting for one of the rolls and means for mounting the otherroll for movement towards and away from one roll in response to itseccentric movement and tensioning of the roving.

2. The method of continuously treating a portion of a multiple lamenthigh denier rayon roving which comprises substantially submerging theroving and repeatedly changing the tension of the submerged portion bysimple harmonic motion, and laterally and longitudinally oscillating theroving during its passage through the bath with'simple harmonic motion.

JOHN P. TARBOX.

